As is known in the medical field, the term “clinical drug treatment study” or “clinical drug trial” (or more simply a “clinical trial”), refers to the testing done on humans to determine the value of a given drug treatment. A clinical drug trial is referred to as a “controlled drug trial” when the effect of a drug treatment is measured against a comparison treatment or treatments administered over the same time period and under similar conditions. In the most typical from of controlled clinical trial, the comparison treatment is provided by supplying a placebo to test study participants in place of the actual treatment (placebo-controlled clinical trial).
As is also known, the term “blinding” in a clinical drug trial refers to the concealment of treatment assignment in order to prevent influencing the behavior, observation or reporting of the person receiving the treatments or of the person administering the treatment. In a double blind, clinical drug trial, both the persons receiving the treatment and the persons administering the treatment are unaware of which study participants are receiving which treatments.
As is also known, the term “randomization” in a clinical drug trial refers to the random assignment to treatment, so that a random sequence determines whether a given subject is assigned to active treatment(s) or placebo. Randomization is an important aspect of a clinical trial in that it eliminates possible biases in treatment assignment.
The purpose of a randomized, double-blind, placebo-controlled trial is to compare the efficacy of a specific treatment or treatments with that of placebo for study participants identified according to a priori criteria and assigned by chance to a given treatment group. The conventional design of such a trial involves the parallel comparison of one or more treatments with placebo, with sample sizes considered adequate to detect a therapeutic signal, given the expected placebo response rates in that specific population. As the term is commonly used, “placebo response” represents an apparent improvement in the clinical condition of study participants randomly assigned to the placebo treatment, (e.g., a pre-post treatment change within the placebo group). It is not uncommon for clinical trials to yield uninterpretable results, due in part to the placebo response. It has been suggested that addressing the placebo response issue is one of the most important challenges facing the future of industry-sponsored psychopharmacologic drug development.